Charge forming device discharge nozzle



Sept. 27, 1966 M. J. THOMAS 3,

CHARGE FORMING DEVICE DISCHARGE NOZZLE Filed Feb. 5, 1964 MIC/IAIL J'- THOMAS INVENTOR ATTOREYS United States Patent Office 3,275,308 Patented Sept. 27, 1966 3,275,308 CHARGE FORMING DEVICE DISCHARGE NOZZLE Michael J. Thomas, Dearborn, Mich, assignor to Ford Motor Company, Deal-born, Mich., a corporation of Delaware Filed Feb. 3, 1964, Ser. No. 342,182 5 Claims. (Cl. 26178) This invention relates to a fuel discharge system for an internal combustion engine charge forming device and more particularly to an adjustable fuel discharge nozzle for a charge forming device.

In a multi-cylinder internal combustion engine, a single induction passage of a charge form'mg device may supply fuel to a plurality of cylinders. The induction passage generally conveys a combustible mixture to each of the cylinders through individual runners of an intake manifold. The mixture distribution system can result in the delivery of uneven strength mixtures to the various cylinders if a uniform mixture is not discharged across the cross section of the induction pass-age of the charge forming device. If the same strength mixture is not supplied to each of the cylinders, it will be necessary to calibrate the charge forming device to satisfy the require- :ments of the leanest cylinder. This will result in the remaining cylinders receiving a richer than necessary charge.

Several factors make it difiicult to insure that a uniform mixture is discharged across the induction passage of a charge forming device. Elements of the charge forming device project into the induction passage and obstruct the air flow. For example, it is a general practice to position an unbalanced choke valve in the induction passage posterior to the fuel discharge nozzle. The choke Valve is supported upon an eccentrically disposed axis so that the air pressure tends to open the choke valve. When the choke valve is fully opened its shaft extends across one side of the induction passage and obstructs the air flow in this area of the induction passage. The attendant uneven air flow past the discharge nozzle results in an uneven fuel discharge. A supporting portion of the fuel discharge nozzle also extends into the induction passage. The supporting portion it self will obstruct the air flow through a section of the induction passage.

The uneven air fiow past the fuel discharge nozzle can be compensated for by proper positioning of the discharge orifices of the discharge nozzle. The correct orifice position may vary from carburetor to carburetor and, in a given carburetor, from engine to engine depending upon such factors as manifold design and cylinder firing order.

It, therefore, is the principal object of this invention to provide a fuel discharge nozzle for a charge forming device that is adjustable to provide a uniform mixtur discharge.

It is a further object of this invention to provide an adjustable discharge nozzle that may be conveniently adjusted and fixed in the adjusted position to suit the requirements of individual engines.

A charge forming device embodying this invention has an induction passage, a fuel source, and a main fuel discharge for discharging fuel from the fuel source into the induction passage. The main fuel discharge includes the discharge nozzle support that extends into the induction passage. The fuel channel extends through the discharge nozzle support. A fuel discharge nozzle is supported by the discharge nozzle support for angular adjustment about an axis that extends in the same direction of the longitudinal axis of the induction passage. The discharge nozzle has discharge ports that extend from the fuel channel into the induction passage. A locking means is provided to retain the discharge nozzle in its angularly adjusted position.

Further objects of this invention will become more apparent when considered in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a side elevational view, with portions shown in section, of a charge forming device embodying this invention.

FIGURE 2 is a top plan view taken in the direction of the line 22 of FIGURE 1.

FIGURE 3 is a side elevational view of the fuel discharge nozzle shown in FIGURES 1 and 2.

Referring now in detail to the drawings, the reference numeral 11 indicates a charge forming device embodying this invention. Change forming device 11 includes a main body portion 12 forming a fuel bowl 13 and an induction passage 14 including a venturi section 15. A throttle valve 16 is positioned upon a throttle valve shaft 17 in the induction passage 14 posterior to the venturi section 15. The body portion 12 is adapted to be supported upon an intake manifold 18 (shown partially) of an internal combustion engine. An inlet passage 19 of the intake manifold 18 registers with the induction passage 14 of the charge forming device 11.

A cover plate 21 is affixed to the body portion 12 by a plurality of bolts 22. The cover plate 21 has an air horn 23 having an air inlet opening 24 in registry with the body portion induction passage 14. A choke valve 25 is supported upon a choke valve shaft 26 in the air horn 23 to provide cold starting enrichment. The choke valve shaft 26 is positioned asymmetrically in the air horn 23 and is disposed to one side of the choke valve 25 so that the choke valve 25 is unbalanced. The unbalanced choke valve 25 is urged toward an open position by the suction in the induction passage 14 posterior to the choke valve 25, when the engine is operating. The choke valve 25 may be positioned manually or by means of any of the known automatic choke actuating mechanisms.

A transverse fuel channel 27 extends through the body portion 12 from below the fuel bowl 13 toward the induction passage 14. A main metering valve (not shown) is positioned at the mouth of the transverse fuel channel 27 to regulate the rate of fuel discharge. The transverse fuel channel 27 terminates at the lower end of a main fuel Well 28 formed in the body portion .12 adjacent the induction passage 14. A discharge nozzle assembly, indicated generally by the reference numeral 29, is provided to convey fuel from the main fuel well 28 into the induction passage 14 contiguous to the throat of the venturi section 15. The main fuel nozzle assembly 29 includes a mounting portion 31 that is affixed to the charge forming device body portion 12 above the main fuel well 28. An idle tube 32 depends from the mounting portion 31 into the main fuel well 28. A main fuel tube 33 also depends from the mounting portion 31 into the main fuel well 28. The idle and main fuel tubes 32 and 33 may be concentric to each other.

During engine idle operation, fuel is drawn from the main fuel well 28 through the idle tube 32. The fuel passes through an idle jet 34 formed near the top of the mounting portion 31. The fuel is mixed with air that is bled through an idle air bleed 35 formed in the mounting portion 31 to form a fuel air emulsion. This emulsion is discharged into the induction passage 14 downstream from the idle position of the throttle valve 16 by an idle fuel discharge system (not shown).

The discharge nozzle assembly 29 also includes a fuel nozzle supporting portion 36 that extends from the mounting portion 31 into the induction passage 14. The nozzle supporting portion 36 terminates in a cylindrical part 37 that is aligned with the longitudinal axis of the induction passage 14 and the throat of the venturi section 15. A bore 38 extends through the cylindrical part along the axis of the induction passage 14. A fuel channel 39 extends through the nozzle supporting portion 36 from a cavity 40 formed in the mounting portion 31 to the bore 38.

A discharge nozzle, indicated generally by the reference numeral 41 and shown in greater detail in FIGURE 3, has a reduced diameter stem portion 42 that extends through the bore 38 and terminates above the cylindrical part 37. A shoulder 43 of the nozzle 41 abuts the lower side of the cylindrical part 37. A plurality of discharge bars 44, four being shown, extend outwardly and downwardly to the venturi section 15 and terminate contiguous to its throat. A fuel discharge port 45 is formed in each of the discharge bars 44. Each fuel discharge port 45 extends from an annular cavity 46 formed between the stem portion 42 and the bore 38 into the induction passage 14 contiguous to the throat of the venturi section 15.

Referring to FIGURE 2, the angular positioning of the nozzle bars 44, indicated by the angles a a a and a may be uniform to result in a symmetrical arrangement. It is preferred, however, to position at least two of the nozzle bars 44 at different angular relationships to a third of the nozzle bars to provide an asymmetric arrangement, for reasons to be described. In the illustrated embodiment, the angle a a a and a.; are all dissimilar.

The upper end of the shank portion 42 is threaded, as at 47 and has a slot 48 in its upper end. A nut 49, received on the threaded end 47, bears against the upper surface of the cylindrical part 37 to secure the discharge nozzle 41 in a set angular position.

During main fuel discharge, air may enter the main fuel well 28 through a main air bleed (not shown) formed in the mounting portion 31. The air passes through air ports 51 formed in the side of the main fuel tube 33. The air mixes with the fuel and forms a fuel air emulsion that is drawn upwardly through the main fuel tube 33 into the cavity 40. The fuel air emulsion passes through the channel 39 formed in supporting portion 36 and enters the annular cavity 46. The emulsion is discharged from the nozzle bar discharge ports 45 contiguous to the throat of the venturi section 15.

When choke valve 25 is fully opened the choke valve shaft 26 will disturb the air flow through the air horn 23. The nozzle supporting portion 36 will also disturb the air flow. These obstructions in the induction passage 14 can cause different rates of air flow past each of the nozzle bars 44. Unless compensated for, the different rates of air flow will cause each of the nozzle bars 44 to discharge a different amount of fuel. The fuel air mixture passing into the inlet passage 19 of the intake manifold 18 therefore will not be uniform across its cross-sectional area. The resulting mixture distribution to the engine cylinders may also be nonuniform. The discharge nozzle 41 may be angularly adjusted by rotation within the cylindrical part 37 about a longitudinal axis that coincides with the longitudinal axis of the induction passage 14. The angular adjustment is accomplished by loosening the nut 49 and rotating the nozzle 41. When it is observed that a uniform fuel air mixture is being discharged across the discharge end of the induction passage 14, the nozzle 41 is locked in the adjusted position by holding it against rotation with a flat bladed tool inserted in the slot 48. The nut 49 is then tightened. The asymmetric distribution of the nozzle bars 44 insures that a proper adjustment may be made.

It is to be understood that this invention is not limited to the exact construction shown and described, but that various changes and modifications may be made without departing from the scope of the invention as defined by the appended claims.

I claim:

1. A charge forming device comprising an induction passage, a fuel source and a main fuel discharge for discharging fuel from said fuel source into said induction passage, said main fuel discharge including a discharge nozzle support extending into said induction passage and terminating along the longitudinal axis of said induction passage, a bore formed in said discharge nozzle support substantially along the longitudinal axis of said induction passage, a fuel channel extending through said discharge nozzle support and terminating at said bore, a fuel discharge nozzle having a stem portion extending coaxially of said bore and journaled therein, at least a section of said stem portion having a smaller external diameter than the internal diameter of said bore to provide an annual clearance therebetween, a plurality of discharge bars extending from said stem portion outwardly and downwardly into said induction passage, a discharge port extending through each of said discharge bars and communicating with said annular clearance, the upper end of said stern portion terminating adjacent an upper surface of said discharge nozzle support and being externally threaded, and a nut threaded upon said stem for retaining said discharge nozzle in an angularly adjusted position.

2. A charge forming device as defined by claim 1 wherein at least three discharge bars and discharge ports are formed in the fuel discharge nozzle, at least three of said discharge ports opening into the induction passage in such directions as to form different angles between at least three peripherally adjacent ports.

3. An internal combustion engine charge forming device c-omprising an induction passage, a fuel source, and a main fuel discharge for discharging fuel from said fuel source into said induction passage, said main fuel discharge including a discharge nozzle support extending into said induction passage, a fuel channel in said discharge nozzle support, a fuel discharge nozzle supported by said discharge nozzle support for angular adjustment about an axis extending in the same direction as the longitudinal axis of said induction passage, said discharge nozzle having at least three discharge ports extending from said fuel channel and opening into said induction passage in such directions as to form different angles between at least three peripherally adjacent ports, and means for retaining said fuel discharge nozzle in an angular adjusted position.

4. A charge forming device comprising an induction passage, a venturi section formed in said induction passage, a fuel source, and a main fuel discharge for discharging fuel from said fuel source into said induction passage contiguous to the throat of said venturi section, said main fuel discharge including a discharge nozzle support extending into said induction passage anterior to said throat, a fuel channel in said discharge nozzle support, a fuel discharge nozzle supported by said discharge nozzle support for angular adjustment about an axis coincident with the longitudinal axis of said throat, said fuel discharge nozzle having at least three discharge ports extending from said fuel channel and opening into said venturi section in such directions as to form different angles between at least three peripherally adjacent ports, and means for retaining said fuel discharge nozzle in an angularly adjusted position.

5. A charge forming device comprising an induction passage, a fuel source, and a main fuel discharge for discharging fuel from said fuel source into said induction passage, said main fuel discharge including a discharge nozzle support extending into said induction passage and terminating along the longitudinal axis of said induction passage, a bore formed in said discharge nozzle support substantially along the longitudinal axis of said induction passage, a fuel channel extending through said discharge nozzle support and terminating at said bore, a fuel discharge nozzle journaled in said bore for angular adjustment about the longitudinal axis of said induction passage, said fuel discharge nozzle having at least three discharge ports extending from said here and opening into said induction passage in such directions as to form materially difierent angles between at least three peripheral- 1y adjacent ports, and means for retaining said fuel discharge nozzle in an angularly adjusted position.

References Cited by the Examiner UNITED STATES PATENTS 1,453,490 5/1923 Bessom.

2,595,720 4/1952 Snyder 261--65 X 3,168,599 2/1965 Marsee et a1. 261-78 X FOREIGN PATENTS 665,950 7/1963 Canada.

6,870 1908 Great Britain.

HARRY B. THORNTON, Primary Examiner. 

1. A CHARGE FORMING DEVICE COMPRISING AN INDUCTION PASSAGE, A FUEL SOURCE AND A MAIN FUEL DISCHARGE FOR DISCHARGING FUEL FROM SAID FUEL SOURCE INTO SAID INDUCTION PASSAGE, SAID MAIN FUEL DISCHARGE INCLUDING A DISCHARGE NOZZLE SUPPORT EXTENDING INTO SAID INDUCTION PASSAGE AND TERMINATION ALONG THE LONGITUDINAL AXIS OF SAID INDUCTION PASSAGE, A BORE FORMED IN SAID DISCHARGE NOZZLE SUPPORT SUBSTANTIALLY ALONG THE LONGITUDINAL AXIS OF SAID INDUCTION PASSAGE, A FUEL CHANNEL EXTENDING THROUGH SAID DISCHARGE NOZZLE SUPPORT AND TERMINATING AT SAID BORE, A FUEL DISCHARGE NOZZLE HAVING A STEM PORTION EXTENDING COAXIALLY OF SAID BORE AND JOURNALED THEREIN, AT LEAST A SECTION OF SAID STEM PORTION HAVING A SMALLER EXTERNAL DIAMETER THAN THE INTERNAL DIAMETER OF SAID BORE TO PROVIDE AN ANNUAL CLEARANCE THEREBETWEEN, A PLURALITY OF DISCHARGE BARD EXTENDING FROM SAID STEM PORTION OUTWARDLY AND DOWNWARDLY INTO SAID INDUCTION PASSAGE, A DISCHARGE PORT EXTENDING THROUGH EACH OF SAID DISCHARGE BARS AND COMMUNICATING WITH SAID ANNULAR CLEARANCE, THE UPPER END OF SAID STEM PORTION TERMINATING ADJACENT AN UPPER SURFACE OF SAID DISCHARGE NOZZLE SUPPORT AND BEING EXTERNALLY THREADED, AND A NUT THREADED UPON SAID STEM BY RETAINING SAID DISCHARGE NOZZLE IN AN ANGULARLY ADJUSTED POSITION. 